For my own part, I have little room in my small kitchen for single-use tools, and I'm also not wild about plastic. If I can get away with using a knife to do the job, even if it takes a little longer, I'm likely to do that. However, I realize that convenience and frequency often trumps all. I'm not likely to buy the pineapple slicer because I don't eat pineapples that often (for seasonal reasons, not because I wouldn't like to!). However, if I lived in a place where pineapples were abundant and a part of my daily diet, then yeah! Absolutely. Sign me up.

What are your buying criteria? Have any of these fruit tools made a world of difference in your cooking life? Or do you find most of them unnecessary or silly?